These definitions allow to specify the encoding of text
* in the char data type as defined by the platform and the compiler.
* It is enough to determine the code point values of "invariant characters",
* which are the ones shared by all encodings that are in use
* on a given platform.

*
*

Those "invariant characters" should be all the uppercase and lowercase
* latin letters, the digits, the space, and "basic punctuation".
* Also, '\\n', '\\r', '\\t' should be available.